The Democratic Republic of the Congo (DRC), also known as the DR Congo, Congo-Kinshasa, or simply the Congo or less often Zaire, is a country in Central Africa. By land area, it is the second-largest country in Africa and the 11th-largest in the world. Centered on the Congo Basin, most of the country's terrain is covered by dense rainforests and is crossed by many rivers, while the east and southeast are mountainous.